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Cenospheres (Expanded Mineral Materials Containing Alumina and Silica) are a by-product of coal-burning power plants and is a lightweight, inert, hollow sphere filled with air or inert gas. the color of the Cenosphere varies from grey to almost white and their density is about 0.4 – 0.8 g/cm3 (0.014 – 0.029 lb./cu in), which provides them with buoyancy.

A Cenosphere behaves like tiny ball bearings to improve workability, flow under pressure, reduce shrinkage, enhance isotropic properties and reduce resin, binder, or water demand due to their low oil absorption level and high packing factor.


Physically, Cenosphere is hard, rigid, light, waterproof, innoxious, and insulative. By utilizing these characteristics of the Cenosphere it is possible to produce materials with excellent heat-insulating properties.


Cenosphere combines all the advantages of spherical shape with the additional benefits of low density at an economic cost. with low densities, Cenosphere reduces the weight of formulated products.

The SonoAsh process liberates trapped cenospheres creating another valuable revenue stream from a waste product along with other valuable technology metals. 

Formed during the coal combustion process a cenosphere is a lightweight, inert, hollow sphere made largely of silica and alumina and filled with air or inert gas.


They are discharged with the ash slurry to the impoundments and eventually some float to the surface.

Cenospheres have been used for more than 20 years to improve the properties of a
variety of finished consumer products. 

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